The vast majority of modern cardiac surgical operations require cardiopulmonary bypass, which was developed in the 1950s, in order to be performed safely. During cardiopulmonary bypass, large cannulas are inserted into the arterial and venous systems (usually via the aorta and the vena cevae). The cardiopulmonary bypass machine removes deoxygenated blood from the body via the vena cevae, adds oxygen to the blood, and returns it to the circulation by pumping it into the aorta. An aortic “cross clamp” is placed in between the heart and the brachiocephalic artery, which assures that no blood from the aortic cannula enters into the heart, thereby providing the surgeon with a “bloodless field.”
Under normal circumstances this series of events would lead to rapid deoxygenation and death of myocardial tissue. However, cardiac surgeons, with the help of clinical perfusionists, inject cardioplegia solution into the coronary arteries. Cardioplegia solution is a mixture of cold blood and a variety of other substances (e.g. potassium), which perform three critical functions—1) cool the myocardium [which decreases its consumption of oxygen] 2) stop the myocardium from contracting [which also decreases its consumption of oxygen] 3) deliver oxygen to the heart. Cardioplegia is injected approximately every twenty minutes and requires cessation of the operation (because during cardioplegia injection, the heart fills with cardioplegia). While the purpose of cardioplegia is to provide myocardial protection, there is no way to reliably assess its adequacy. Currently, surgeons rely on 1) visualizing mechanical myocardial contraction and 2) visualizing electrical activity on the electrocardiogram (ECG), both of which suggest that the heart is beginning to contract despite its deoxygenated state.
If perfusion is inadequate, patients may suffer irreversible myocardial damage which can lead to either a need for heart transplantation or death. While this occurs rarely, it is a known complication of cardiac surgery.
In patients with significant coronary artery disease, left ventricular hypertrophy, or aortic valve insufficiency, it may be difficult to adequately protect the myocardium by injecting cardioplegia solution through the coronary arteries (the “anterograde” approach). In these cases, surgeons will often place a catheter in the coronary sinus (a large vein which drains the heart) and inject cardioplegia solution into the myocardium in a “retrograde” fashion. This is referred to as “retrograde cardioplegia.”
Overview
The coronary sinus is a unique anatomical structure as it wraps around the left ventricle. An aspect of an embodiment of the present invention provides for the placement of a tissue oxygen monitor on the coronary sinus that would allow the surgeon to monitor the oxygenation status of the left ventricle.
A purpose of an embodiment of the present invention oximetric coronary sinus catheter device and related method is to, but not limited thereto, provide cardiac surgeons, cardiac anesthesiologists, and clinical perfusionists with a means of assessing the oxygenation status of the myocardium during cardiopulmonary bypass for cardiac surgery. Alternatively, a purpose of an embodiment of the present invention pulmonary artery catheter device and related method is to, but not limited thereto, provide cardiac surgeons, cardiac anesthesiologists, and clinical perfusionists with a means of assessing the oxygenation status of the myocardium of the right ventricle during cardiopulmonary bypass for cardiac surgery. Currently there are no clinically available means for assessing myocardial oxygenation during cardiac surgery.
An aspect of an embodiment of the present invention relies on visible spectroscopy (covering a spectrum of approximately 380 to approximately 750 nm) and/or near infrared spectroscopy (NIRS, in which absorbance of electromagnetic radiation in the near infrared [approximately 700 to approximately 1,100 nm] range is utilized to measure non-pulsatile tissue oxygenation status) to estimate the oxygen content of the myocardium. It should be appreciated that the spectroscopy range may also be at a level lower than 380 nm and/or a level greater than 1100 nm as desired, needed or required for operation and effectiveness.
Coronary sinus catheters are generally used by cardiac surgeons to deliver cardioplegia to the heart during surgery.
An aspect of an embodiment of the present invent device provides, among other things, a significant feature/approach that will allow cardiac surgeons, cardiac anesthesiologists, and clinical perfusionists to assess the adequacy of cardioplegia/myocardial protection.
An aspect of an embodiment of the present invention device and method is, but not limited thereto, that it will allow cardiac surgeons, cardiac anesthesiologists, and clinical perfusionists to implement “retrograde cardioplegia” while reducing the risk to the patient and with no additional procedural time.
While some dimensions may be provided or illustrated on the figures or within the description, it should be appreciated that the device may constitute various sizes, dimensions, contours, rigidity, shapes, flexibility and materials as it pertains to the components or portions of components of the device, and therefore may be varied and utilized as desired or required to meet the anatomical and structural demands, operational requirements, and surgical and clinical needs.
It should be appreciated that the related components or portions of the related components as discussed herein may take on all shapes along the entire continual geometric spectrum of manipulation of x, y and z planes to provide and meet the anatomical and structural demands, operational requirements, and surgical and clinical needs.
An aspect of an embodiment of the present invention provides, but not limited thereto, a system for measuring the oxidation state of biological molecules in a region of a measurement site of a subject. The system may comprise: at least one emitter configured to be in optical communication with the region of the measurement site of the subject; at least one detector configured to be in optical communication with the region of the measurement site of the subject; wherein the at least one emitter or the at least one detector is configured to be disposed inside the subject; and the at least one emitter and the at least one detector are in electromagnetic radiation communication with one another, wherein the electromagnetic radiation communication allows visible radiation or near infrared radiation emitted by the at least one emitters to be detected by the at least one detector to determine tissue oxidation state of the region of the measurement site of the subject. Moreover, the system may be configured wherein both the at least one emitter and the at least one detector are configured to be disposed inside the subject. It should be appreciated that the at least one emitter may be an array of emitters or a plurality of emitters or the like. Similarly, it should be appreciated the at least one detector may be an array of detectors or a plurality of detectors or the like.
An aspect of an embodiment of the present invention provides, but not limited thereto, a catheter system for measuring the oxidation state of biological molecules in a region of a measurement site of a subject. The system may comprise: a catheter device having a lumen, the catheter device includes proximal region, a distal regional, and a longitudinal region there between; at least one emitter in mechanical communication with the catheter distal region and configured to make contact with a tissue wall of the subject; at least one detector in mechanical communication with the catheter distal region and configured to make contact with the tissue wall of the subject; and the at least one emitter and the at least one detector are in electromagnetic radiation communication with one another, wherein the electromagnetic radiation communication allows visible radiation or near infrared radiation emitted by the at least one emitters to be detected by the at least one detector to determine tissue oxidation state of the region of the measurement site of the subject. Moreover, the system may comprise an expandable component in mechanical communication with the catheter distal region, and located between the at least one emitter and the at least one detector and the catheter distal region.
An aspect of an embodiment of the present invention provides, but not limited thereto, a method for measuring the oxidation state of biological molecules in a region of a measurement site of a subject. The method may comprise: providing at least one emitter in optical communication with the region of the measurement site of the subject; providing at least one detector in optical communication with the region of the measurement site of the subject; disposing the at least one emitter or the at least one detector inside the subject; and communicating electromagnetic radiation between the at least one emitter and the at least one detector, wherein the electromagnetic radiation communication allows visible radiation or near infrared radiation emitted by the at least one emitters to be detected by the at least one detector to determine tissue oxidation state of the region of the measurement site of the subject. Moreover, the method may comprise disposing both the at least one emitter and the at least one detector inside the subject.
An aspect of an embodiment of the present invention provides, but not limited thereto, a method for measuring the oxidation state of biological molecules in a region of a measurement site of a subject. The method may comprise: providing a catheter device having a lumen, the catheter device includes proximal region, a distal regional, and a longitudinal region there between; providing at least one emitter configured to make contact with a tissue wall of the subject; providing at least one detector configured to make contact with the tissue wall of the subject; and communicating electromagnetic radiation between the at least one emitter and the at least one detector, wherein the electromagnetic radiation communication allows visible radiation or near infrared radiation emitted by the at least one emitters to be detected by the at least one detector to determine tissue oxidation state of the region of the measurement site of the subject. Moreover, the method may comprise providing an expandable component in mechanical communication with the catheter distal region, and located between the at least one emitter and the at least one detector and the catheter distal region.
A catheter system and related method for measuring the oxidation state of biological molecules in a region of a measurement site of a subject. The system may include a catheter device having one or more emitters in mechanical communication with the catheter and configured to make contact with a tissue wall of the subject. The catheter device also includes one or more detectors in mechanical communication with the catheter and configured to make contact with the tissue wall of the subject. The emitters and the detector are in electromagnetic radiation communication with one another, whereby the electromagnetic radiation communication allows visible radiation or near infrared radiation emitted by emitters to be detected by the detector to determine tissue oxidation state of the region of the measurement site of the subject. Moreover, the system may include an expandable component in communication with the catheter device configured to assure that the at least one emitter and the at least one detector makes contact with the tissue wall.
These and other objects, along with advantages and features of various aspects of embodiments of the invention disclosed herein, will be made more apparent from the description, drawings and claims that follow.